CN112582807B

CN112582807B - Directional antenna and communication equipment

Info

Publication number: CN112582807B
Application number: CN201910927624.0A
Authority: CN
Inventors: 余敏; 罗昕; 舒余平; 陈一
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-09-27
Filing date: 2019-09-27
Publication date: 2021-12-28
Anticipated expiration: 2039-09-27
Also published as: CN112582807A; US20220216606A1; EP4030560A4; WO2021057627A1; EP4030560A1

Abstract

A directional antenna and a communication apparatus are provided. The directional antenna includes an active element and a first reflector. The active oscillator comprises a first oscillator and a second oscillator, the working frequency band of the first oscillator is a first frequency band, and the working frequency band of the second oscillator is a second frequency band. The equivalent electrical length of the first reflector is equal to or slightly greater than one half of the wavelength of the first frequency band, the first reflector comprises a first resonant circuit, the first resonant circuit comprises a first capacitive element and a first inductive element which are connected in parallel, the resonant frequency of the first resonant circuit is within the second frequency band, and the equivalent electrical length of a part, except the first resonant circuit, of the first reflector is smaller than one half of the wavelength of the second frequency band. In the directional antenna and the communication equipment, the first reflector can perform directional reflection on the electromagnetic wave sent by the first oscillator, so that the gain of the directional antenna in the reflection direction is improved.

Description

Directional antenna and communication equipment

Technical Field

The application relates to the technical field of communication, in particular to a directional antenna and communication equipment.

Background

The signal of the omni-directional antenna covers all directions uniformly and cannot be changed. The omnidirectional antenna cannot concentrate the radiation energy to the direction of the user according to the position of the user, and cannot realize directional radiation, so that the gain of the antenna in a specific direction is small.

Disclosure of Invention

The application provides a directional antenna and communication equipment, which are used for directionally radiating electromagnetic waves and improving the gain of the antenna in a specific direction.

The directional antenna includes an active element and a first reflector. The active vibrator includes a first vibrator and a second vibrator. The working frequency band of the first oscillator is a first frequency band, and the working frequency band of the second oscillator is a second frequency band. The equivalent electrical length of the first reflector is equal to or slightly greater than one-half of the wavelength of the first frequency band. Wherein the first reflector comprises a first resonant circuit comprising a first capacitive element and a first inductive element connected in parallel. The resonance frequency of the first resonance circuit is located in the second frequency band, and the equivalent electrical length of the part of the first reflector except the first resonance circuit is less than one half of the wavelength of the second frequency band.

In the directional antenna, since the equivalent electrical length of the first reflector is equal to or slightly greater than one-half of the wavelength of the first frequency band, the electromagnetic wave having a frequency within the first frequency band resonates on the first reflector. When the electromagnetic wave transmitted by the first oscillator is transmitted to the first reflector, the electromagnetic wave induced by the first reflector and the electromagnetic wave transmitted by the first oscillator generate constructive interference in one direction to strengthen the electromagnetic wave, and generate destructive interference in the other direction to weaken the electromagnetic wave. The first reflector is equivalent to reflect the electromagnetic wave emitted by the first oscillator, so that the gain of the directional antenna in the reflection direction is enhanced, and the communication quality is improved.

When the electromagnetic wave emitted by the second oscillator is transmitted to the first reflector, because the resonant frequency of the first resonant circuit is located in the second frequency band, that is, the resonant frequency of the first resonant circuit is close to the second frequency band, the electromagnetic wave emitted by the second oscillator resonates in the first resonant circuit to be in a high-impedance state, and the first resonant circuit in the high-impedance state is similar to an insulator. The first resonant circuit in the high impedance state blocks an induced current generated on the first reflector by an electromagnetic wave having a frequency within the second frequency band, so that the induced current is only generated in a portion of the first reflector except the first resonant circuit. Since the equivalent electrical length of the portion of the first reflector except for the first resonant circuit is less than one-half of the wavelength of the second frequency band, the first reflector does not resonate in the second frequency band. Therefore, the first reflector is transparent to the electromagnetic wave emitted by the second oscillator, that is, the first reflector does not generate interference such as strong reflection and scattering to the electromagnetic wave emitted by the second oscillator, that is, the first reflector hardly influences the normal propagation of the electromagnetic wave emitted by the second oscillator.

In a word, when the directional antenna works, the first reflector can reflect the electromagnetic waves emitted by the first oscillator and can not distort the electromagnetic waves emitted by the second oscillator. The first reflector can selectively reflect the electromagnetic waves of a specific frequency band of the two frequency bands, so that the beam modes of the directional antenna in the first frequency band and the second frequency band are independent of each other, and the directional antenna can work in the dual-frequency band according to the independent directional mode.

In one embodiment, the equivalent electrical length of the first vibrator is equal to one half of the wavelength of the first frequency band to transmit and receive electromagnetic waves with a frequency in the first frequency band, and the equivalent electrical length of the second vibrator is equal to one half of the wavelength of the second frequency band to transmit and receive electromagnetic waves with a frequency in the second frequency band.

In one embodiment, the minimum frequency of the second frequency band is greater than the maximum frequency of the first frequency band.

In the directional antenna according to this embodiment, any frequency in the second frequency band is greater than the frequency in the first frequency band, that is, the first frequency band is a low frequency band, and the second frequency band is a high frequency band, at this time, the first reflector is transparent to the electromagnetic waves with higher frequency and reflects the electromagnetic waves with lower frequency, that is, the first reflector is a low frequency reflector that reflects the electromagnetic waves with low frequency band and is transparent to the electromagnetic waves with high frequency band. That is to say, the first reflector can reflect low-frequency electromagnetic waves without affecting normal propagation of high-frequency electromagnetic waves, and the first reflector can selectively reflect low-frequency electromagnetic waves in multiple frequency bands, so that the directional antenna is independent of beam modes in the low-frequency band and the high-frequency band, and can operate in dual-frequency bands according to independent directional modes.

In one embodiment, the maximum frequency in the second frequency band is less than the minimum frequency in the first frequency band.

In the directional antenna according to this embodiment, any frequency in the second frequency band is smaller than the frequency in the first frequency band, that is, the first frequency band is a high frequency band, and the second frequency band is a low frequency band, at this time, the first reflector is transparent to the electromagnetic wave with a lower frequency and reflects the electromagnetic wave with a higher frequency, and the first reflector is a high frequency reflector that reflects the electromagnetic wave with a higher frequency and is transparent to the electromagnetic wave with a lower frequency.

In one embodiment, the active oscillator further includes a third oscillator, an operating frequency band of the third oscillator is a third frequency band, and the first reflector further includes a second resonant circuit connected in series with the first resonant circuit;

the second resonant circuit comprises a second capacitive element and a second inductive element which are connected in parallel, and the resonant frequency of the second resonant circuit is located in the third frequency band.

When the electromagnetic wave emitted by the third oscillator is transmitted to the first reflector, because the resonant frequency of the second resonant circuit is located in the third frequency band, that is, the resonant frequency of the second resonant circuit is close to the third frequency band, the electromagnetic wave emitted by the third oscillator will resonate in the second resonant circuit and is in a high-impedance state, that is, the second resonant circuit is equivalent to an insulator. The second resonant circuit in the high impedance state blocks induced current generated on the first reflector by electromagnetic waves in the third frequency band, so that the first reflector does not resonate in the third frequency band. Therefore, the first reflector is transparent to the electromagnetic wave emitted by the third oscillator, that is, the first reflector does not generate interference such as scattering of strong reflection to the electromagnetic wave emitted by the third oscillator, that is, the first reflector hardly influences the normal propagation of the electromagnetic wave emitted by the third oscillator.

That is, in the operation of the directional antenna according to the present embodiment, the first reflector may reflect the electromagnetic wave emitted from the first oscillator without distorting the electromagnetic wave emitted from the second oscillator and the third oscillator. The first reflector can selectively reflect electromagnetic waves of a specific frequency band of the three frequency bands, so that the beam modes of the directional antenna in the first frequency band, the second frequency band and the third frequency band are mutually independent, and the directional antenna can work in the three frequency bands according to the independent directional modes.

In one embodiment, the equivalent electrical length of the third element is equal to one half of the wavelength of the third frequency band, so as to transmit and receive electromagnetic waves with frequencies in the third frequency band.

In one embodiment, the first reflector further includes a conductive member connected in series with the first resonant circuit, and the equivalent electrical length of the first reflector minus the equivalent electrical length of the conductive member is less than one-half of the wavelength of the first frequency band.

When the equivalent electrical length of the first resonant circuit is less than one-half of the wavelength of the first frequency band, the additional arrangement of the conductive member can increase the mechanical length of the first reflector, so as to complement the equivalent electrical length of the first reflector, so that the equivalent electrical length of the first reflector is equal to or slightly greater than one-half of the wavelength of the first frequency band, and the first reflector can reflect the electromagnetic wave emitted by the first oscillator.

In one embodiment, the directional antenna further comprises a second reflector, and the equivalent electrical length of the second reflector is equal to or slightly greater than one-half of the wavelength of the second frequency band, so that electromagnetic waves with frequencies in the second frequency band can resonate on the second reflector. When the electromagnetic wave transmitted by the second oscillator is transmitted to the second reflector, the electromagnetic wave sensed by the second reflector and the electromagnetic wave transmitted by the second oscillator generate constructive interference in one direction to be strengthened, and generate destructive interference in the other direction to be weakened, which is equivalent to that the second reflector reflects the electromagnetic wave transmitted by the second oscillator, so that the gain of the directional antenna in the reflection direction is enhanced, and the communication quality is improved.

In one embodiment, the directional antenna further comprises a mounting plate, the mounting plate comprises a first mounting surface, a first functional layer is arranged on the first mounting surface, the active oscillator is located in the first functional layer, and the active oscillator can be formed on the first mounting surface through a printing process, so that the forming process of the active oscillator is simplified.

In one embodiment, the first capacitive element and the first inductive element are both located in the first functional layer and can be formed in the same process as the active element, and no additional process is required to form the first capacitive element and the first inductive element, thereby saving the manufacturing cost of the directional antenna. In addition, the first capacitive part and the first inductive part are both located in the first functional layer, that is, the first capacitive part and the first inductive part are both physical structures, and do not need to be assembled on the mounting surface through a welding process, so that parasitic effects generated by welding and other procedures are avoided.

In one embodiment, the material of the first functional layer is a conductor such as a metal.

In an embodiment, the mounting board further includes a second mounting surface disposed opposite to the first mounting surface, a second functional layer is disposed on the second mounting surface, the first capacitive element and the second inductive element are both located in the second functional layer, or the first capacitive element and the second inductive element are respectively located in the first functional layer and the second functional layer, and the first capacitive element and the first inductive element are disposed opposite to each other, so as to reduce a lateral size of the first resonant circuit, further reduce a lateral size of the first reflector, improve a structural compactness of the directional antenna, and facilitate a miniaturized design of the directional antenna.

In some embodiments, the material of the second functional layer is a conductor such as a metal.

In one embodiment, the first capacitive element includes a plurality of metal blocks arranged at intervals and a gap between the metal blocks, and the shape of the gap includes, but is not limited to, a straight line, a broken line, a curved line, and the like.

In one embodiment, the first sensing member comprises a metal wire with a waveform, and the shape of the waveform includes, but is not limited to, a rectangular wave, a sawtooth wave, a sine wave, and the like.

In one embodiment, the directional antenna further includes a floor, the floor includes a bearing surface, the bearing surface bears the mounting plate, an included angle between the bearing surface and the first mounting surface is equal to 90 degrees, a conductive layer is disposed on the bearing surface, and the conductive layer is electrically connected to the active oscillator and the first reflector.

In the directional antenna according to this embodiment, the conductive layer mirrors the active element and the first reflector, and according to the principle of mirroring electromagnetic waves, at this time, the equivalent electrical length of the first element is equal to the sum of the electrical lengths of the mirror images of the first element and the first element on the conductive layer, the equivalent electrical length of the second element is equal to the sum of the electrical lengths of the mirror images of the second element and the second element on the conductive layer, and the equivalent electrical length of the first reflector is equal to the sum of the electrical lengths of the mirror images of the first reflector and the first reflector on the conductive layer. That is to say, the directional antenna in this embodiment employs the conductive layer to mirror the active oscillator and the first reflector, so that the sizes of the active oscillator and the first reflector can be reduced, and thus the size of the directional antenna is reduced, the manufacturing cost of the directional antenna is saved, the structural compactness of the directional antenna is improved, and the directional antenna is advantageous for miniaturization design.

In one embodiment, the conductive layer is further electrically connected to the second reflector for mirroring the second reflector and reducing the size of the second reflector, so as to reduce the size of the directional antenna, save the manufacturing cost of the directional antenna, improve the compactness of the directional antenna, and facilitate the miniaturization design of the directional antenna.

In one embodiment, the conductive layer is made of a conductor such as a metal.

In one embodiment, the floor is made of metal, and the floor and the conductive layer are integrally formed metal plates, so as to simplify the manufacturing process of the directional antenna and save the production cost of the directional antenna.

In one embodiment, the first reflector further comprises a control switch in series with the first resonant circuit and electrically connected between the first resonant circuit and the conductive layer;

when the control switch is closed, the sum of the electrical length of the first reflector and the electrical length of the mirror image of the first reflector on the conductive layer is equal to or slightly larger than one half of the wavelength of the first frequency band.

In the directional antenna according to this embodiment, the control switch is used to control an electrical connection state between the first resonant circuit and the conductive layer, that is, a conduction state between the first reflector and the conductive layer, so that when the directional antenna is in operation, on/off of the first reflector and the conductive layer can be selected according to specific requirements, so as to control whether the first reflector reflects electromagnetic waves emitted by the first oscillator.

In one embodiment, the control switch includes, but is not limited to, a PIN diode, a micro-electromechanical system switch, or a photoelectric switch.

In one embodiment, the frequency of the second frequency band is approximately twice the frequency of the first frequency band, i.e. the wavelength of the electromagnetic wave with the frequency in the first frequency band is approximately twice the wavelength of the electromagnetic wave with the frequency in the first frequency band.

In the directional antenna shown in this embodiment, the electrical length of the first reflector is equal to or slightly greater than a quarter of the wavelength of the first frequency band, that is, the mechanical length of the first reflector is equal to or slightly greater than a quarter of the wavelength of the first frequency band, and then the mechanical length of the first reflector is equal to or slightly greater than a half of the wavelength of the second frequency band. If the electromagnetic wave emitted by the second oscillator is transmitted to the first reflector, the first resonant circuit is close to an insulator, and an induced current can be generated in the first reflector except the first resonant circuit. Although the mechanical length of the first reflector is equal to or slightly greater than one-half of the wavelength of the second frequency band, the equivalent electrical length of the portion of the first reflector except the first resonant circuit is less than one-half of the wavelength of the second frequency band, and the first reflector does not resonate in the second frequency band and is transparent to the electromagnetic wave emitted by the second oscillator.

In one embodiment, an included angle between the bearing surface and the first mounting surface is less than 90 degrees.

The communication equipment comprises a radio frequency module and any one of the directional antennas, wherein the radio frequency module is electrically connected with an active oscillator of the directional antenna and used for sending electromagnetic signals to the active oscillator of the directional antenna and receiving the electromagnetic signals received by the active oscillator.

Communication equipment includes above-mentioned directional antenna, directional antenna during operation, first reflector can reflect the electromagnetic wave of first oscillator transmission can not influence again the normal propagation of the electromagnetic wave of second oscillator transmission. The first reflector can selectively reflect electromagnetic waves of a specific frequency band in the two frequency bands, so that beam modes of the directional antenna in the first frequency band and the second frequency band are independent of each other, and the directional antenna can work in dual frequency bands according to the independent directional modes.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be described below.

Fig. 1 is a schematic structural diagram of a communication device according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of a directional antenna provided in an embodiment of the present application;

fig. 3 is a schematic cross-sectional view of the directional antenna shown in fig. 2 along the direction a-a;

FIG. 4 is a schematic diagram of a first reflector and a first element of the directional antenna shown in FIG. 2;

FIG. 5 is a detailed structural schematic diagram of a first resonant circuit in the first reflector shown in FIG. 2;

FIGS. 6A-6E are schematic structural diagrams of alternative embodiments of the first capacitive element of the first resonant circuit of FIG. 5;

FIGS. 7A-7D are schematic structural diagrams of other embodiments of the first inductive element in the first resonant circuit of FIG. 5;

FIG. 8 is a schematic diagram of a simulation design using the first resonant circuit shown in FIG. 5 as a transmission line;

FIG. 9 is a graph of a two-port S parameter obtained after a simulation test of the structure shown in FIG. 8;

fig. 10A is a beam pattern of the directional antenna of fig. 2 at 2.4 GHz;

fig. 10B is a beam pattern at 5GHz for the directional antenna of fig. 2;

fig. 11 is a schematic structural diagram of a second directional antenna provided in an embodiment of the present application;

FIG. 12 is a schematic cross-sectional view of the directional antenna shown in FIG. 11 along the direction B-B

Fig. 13 is a schematic structural diagram of a third directional antenna provided in the embodiment of the present application;

fig. 14 is a schematic cross-sectional view of the directional antenna shown in fig. 13 along the direction C-C;

fig. 15 is a schematic structural diagram of a fourth directional antenna provided in the embodiment of the present application;

fig. 16 is a schematic cross-sectional view of the directional antenna shown in fig. 15 along the direction E-E;

fig. 17 is a schematic structural diagram of a fifth directional antenna provided in an embodiment of the present application;

fig. 18 is a schematic cross-sectional view of the directional antenna shown in fig. 17 along the F-F direction;

fig. 19 is a schematic diagram of a partial structure of the directional antenna 10 shown in fig. 17;

fig. 20 is a schematic structural diagram of a sixth directional antenna provided in an embodiment of the present application;

fig. 21 is a schematic cross-sectional view of the directional antenna shown in fig. 20 along the G-G direction;

fig. 22 is a schematic structural diagram of a seventh directional antenna provided in the embodiment of the present application.

Detailed Description

The following description will be made with reference to the drawings in the embodiments of the present application.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a communication device 100 according to an embodiment of the present disclosure.

The communication device 100 provided in the embodiment of the present application includes, but is not limited to, a cellular base station, a Wireless Local Area Network (WLAN) device, a mobile phone, a tablet computer, a computer, or a wearable device and other electronic products with a wireless communication function. The communication device 100 includes a directional antenna 10, a device body 20, and a radio frequency module 30. The directional antenna 10 and the radio frequency module 30 are mounted on the apparatus body 20. The rf module 30 is electrically connected to the directional antenna 10, and is configured to transmit and receive electromagnetic signals to and from an active element (not shown) of the directional antenna 10 through the feeding point 21. The directional antenna 10 radiates electromagnetic waves according to the received electromagnetic signals or transmits electromagnetic signals to the radio frequency module 30 according to the received electromagnetic waves, thereby realizing the transceiving of wireless signals. The Radio Frequency module (AF module)30 is a circuit such as a transceiver and/or receiver (T/R) that can transmit and/or receive Radio Frequency signals.

Please refer to fig. 2 and 3. Fig. 2 is a schematic structural diagram of a directional antenna 10 according to an embodiment of the present application, where the directional antenna 10 corresponds to the directional antenna 10 in the communication device 100 shown in fig. 1. Fig. 3 is a schematic cross-sectional view of the directional antenna 10 shown in fig. 2 along the direction a-a, wherein the schematic cross-sectional view along the direction a-a is a schematic cross-sectional view of the directional antenna 10 taken along the position of the dashed dotted line.

The directional antenna 10 comprises a mounting board 1, an active element 2 and a first reflector 3 and a floor 4. The mounting board 1 includes a first mounting surface 101, and the active vibrator 2 and the first reflector 3 are provided on the first mounting surface 101. The active oscillator 2 comprises a first oscillator 23 and a second oscillator 22, the working frequency band of the first oscillator 23 is a first frequency band, and the working frequency band of the second oscillator 22 is a second frequency band. The equivalent electrical length (electrical length) of the first reflector 3 is equal to or slightly greater than one-half of the wavelength of the first frequency band. The first reflector 3 comprises a first resonant circuit 31, the first resonant circuit 31 comprises a first capacitive element 311 and a first inductive element 312 which are connected in parallel, and the resonant frequency of the first resonant circuit 31 is in the second frequency band. The equivalent electrical length of the part of the first reflector 3 other than the first resonant circuit 31 is less than one-half of the wavelength of said second band. The floor 4 comprises a bearing surface 401, the bearing surface 401 bears the mounting board 1, an included angle between the mounting board 401 and the first mounting surface 101 is equal to 90 degrees, a conductive layer 41 is arranged on the bearing surface 401, and the conductive layer 41 is electrically connected with the active oscillator 2 and the first reflector 3. In this embodiment, when a component is electrically connected to the conductive layer 41, the equivalent electrical length of the component is equal to the sum of the actual electrical length of the component and the electrical length of the component mirrored at the conductive layer 41, i.e., the equivalent electrical length of the component is equal to twice the actual electrical length of the component; when the component is not electrically connected to the conductive layer 41, the equivalent electrical length of the component is equal to the actual electrical length of the component. The electrical length refers to a ratio of a mechanical length (also referred to as a physical length or a geometric length) of a propagation medium or structure to a wavelength of an electromagnetic wave propagating on the medium or structure.

In the directional antenna 10 shown in this embodiment, since the equivalent electrical length of the first reflector 3 is equal to or slightly greater than one-half of the wavelength of the first frequency band, the electromagnetic wave with a frequency in the first frequency band resonates on the first reflector 3. When the electromagnetic wave emitted by the first oscillator 23 is transmitted to the first reflector 3, the electromagnetic wave induced by the first reflector 3 and the electromagnetic wave emitted by the first oscillator 31 constructively interfere in one direction to be strengthened, and destructively interfere in the other direction to be weakened. The first reflector 3 reflects the electromagnetic wave emitted by the first oscillator 23, so that the gain of the directional antenna 10 in the reflection direction is enhanced, and the communication quality is improved.

When the electromagnetic wave emitted by the second oscillator 22 is transmitted to the first reflector 3, since the resonant frequency of the first resonant circuit 31 is in the second frequency band, that is, the resonant frequency of the first resonant circuit 31 is close to the second frequency band, the first resonant circuit 31 resonates to be in a high-impedance state, and the first resonant circuit 31 in the high-impedance state is similar to an insulator. The first resonant circuit 31 in the high impedance state blocks the induced current generated on the first reflector 3 by the current with the frequency in the second frequency band, so that only the part of the first reflector 3 except the first resonant circuit 31 can generate the induced current. Since the equivalent electrical length of the portion of the first reflector 3 other than the first resonant circuit 31 is less than one-half of the wavelength of the second frequency band, the first reflector 3 does not resonate in the second frequency band. Therefore, the first reflector 3 appears transparent to the electromagnetic waves emitted by the second vibrator 22, i.e. the first reflector 3 hardly affects the normal propagation of the electromagnetic waves emitted by the second vibrator 22.

That is, when the directional antenna 10 shown in the present embodiment is operated, the first reflector 3 can reflect the electromagnetic wave emitted from the first oscillator 23, and does not generate strong interference such as reflection and scattering on the electromagnetic wave emitted from the second oscillator 22, and does not distort the electromagnetic wave emitted from the second oscillator 22. Since the first reflector 3 can selectively reflect the electromagnetic wave of a specific frequency band of the two frequency bands, the beam modes of the directional antenna 10 in the first frequency band and the second frequency band are independent of each other, and the directional antenna can operate in the dual frequency bands according to the independent directional mode.

In this embodiment, the mounting Board 1 is a Printed Circuit Board (PCB), and the first functional layer 11 is disposed on the first mounting surface 101 of the mounting Board 1. Specifically, the material of the first functional layer 11 is copper, that is, the first functional layer 11 is a copper layer disposed on the first mounting surface 101. In one embodiment, the first functional layer 11 is printed on the first mounting surface 101. In other embodiments, the mounting board may also be another substrate having a bearing function, and the material of the first functional layer may also be another conductor, which is not specifically limited in this application.

The active vibrator 2 is located in the middle area of the first mounting surface 101. The active resonator 2 is located in the first functional layer 11 and can be printed on the first mounting surface 101, so that the preparation process of the active resonator 2 is simplified. Specifically, the active oscillator 2 extends along the X-axis direction of the first mounting surface 101, a feeding point 21 is disposed at the bottom of the active oscillator 2, the feeding point 21 is connected to the radio frequency module 30 through a feeder (not shown), and the active oscillator 2 receives an electromagnetic signal transmitted by the radio frequency module 30 through the feeding point 21 or transmits a received external electromagnetic signal to the radio frequency module 30. In one embodiment, the feeder is a transmission line formed by two conductors, two conductors at one end of the transmission line are electrically connected to the feeding point 21 and the conductive layer 41, respectively, and the other end of the transmission line is electrically connected to the port of the rf module 30. In this embodiment, the X-axis direction of the first mounting surface 101 is a direction perpendicular to the mounting surface 401 on the first mounting surface 101.

The active vibrator 2 includes one first vibrator 23 and two second vibrators 22. Specifically, the first oscillator 23 extends along the X-axis direction, and the equivalent electrical length of the first oscillator 23 is equal to the wavelength λ of the first frequency band₁Is used for transmitting or receiving electromagnetic waves with the frequency located in the first frequency band. In the present embodiment, the sum of the electrical lengths of the mirrors of the first vibrator 23 in the conductive layer 41 is equal to the equivalent electrical length of the first vibrator 23. Because the included angle between the first mounting surface 101 and the mounting surface 401 is 90 degrees, the electrical length of the first vibrator 23 is equal to the electrical length of the mirror image of the first vibrator 23 on the conductive layer 41, that is, twice the electrical length of the first vibrator 23 is equal to the equivalent electrical length of the first vibrator 23, and at this time, the electrical length of the first vibrator 23 is equal to one quarter of the wavelength of the first frequency band.

The two second vibrators 22 are symmetrically distributed on two sides of the first vibrator 23, and a gap exists between each second vibrator 22 and the first vibrator 23. The equivalent electrical length of the second element 22 is equal to the wavelength λ of said second frequency band₂Is used for transmitting or receiving electromagnetic waves with the frequency located in the second frequency band. In this embodiment, second transducer 22 and the projection of second transducer 22 on conductive layer 41The sum of the electrical lengths is equal to the equivalent electrical length of the second transducer 22. Because the included angle between the first mounting surface 101 and the bearing surface 401 is 90 degrees, the electrical length of the second oscillator 22 is equal to the electrical length of the mirror image of the second oscillator 22 on the conductive layer 41, that is, twice the electrical length of the second oscillator 22 is equal to the equivalent electrical length of the second oscillator 22, and at this time, the electrical length of the second oscillator 22 is equal to one quarter of the wavelength of the second frequency band.

In this embodiment, the minimum frequency in the second frequency band is greater than the maximum frequency of the first frequency band, i.e. λ₂＜λ₁. That is, the operating frequency band of the first oscillator 23 is a low frequency band, the operating frequency band of the second oscillator 22 is a low frequency band, and the first reflector 3 is a low frequency reflector that reflects low frequency band electromagnetic waves and is transparent to high frequency band electromagnetic waves. In one embodiment, the frequency of the second frequency range is approximately twice the frequency of the first frequency range, i.e. 2 λ₂≈λ₁. In other embodiments, the frequency of the second frequency band may also be similar to other multiples of the frequency of the first frequency band, which is not specifically limited in this embodiment.

Because the equivalent electrical length of the low-frequency reflector in the low-frequency band is equal to or slightly greater than one half of the wavelength of the low-frequency band, the equivalent electrical length of the low-frequency reflector in the high-frequency band is greater than one half of the wavelength of the high-frequency band, and when the electromagnetic wave in the high-frequency band is transmitted to the low-frequency reflector, the low-frequency reflector can generate interference such as strong reflection, scattering and the like on the electromagnetic wave in the high-frequency band, so that the electromagnetic wave in the high-frequency band is distorted. In the directional antenna 10 shown in this embodiment, the first reflector 3 not only reflects low-frequency-band electromagnetic waves, but also is transparent to high-frequency-band electromagnetic waves, so that the high-frequency-band electromagnetic waves are not interfered, and the high-frequency-band electromagnetic waves are transmitted to the first reflector 3 without distortion and keep normal propagation, and the first reflector 3 can selectively reflect dual-band low-frequency-band and low-frequency-band electromagnetic waves, so that the beam modes of the directional antenna 10 in the low-frequency band and the high-frequency band are independent of each other, and can operate in the dual-band according to the independent directional mode. In other embodiments, the maximum frequency in the second frequency band may also be smaller than the minimum frequency in the first frequency band, that is, the operating frequency band of the first oscillator is a high frequency band, and the operating frequency band of the second oscillator is a low frequency band, which is not specifically limited in this embodiment.

Referring to fig. 4, fig. 4 is a schematic structural diagram of the first reflector 3 and the first element 23 in the directional antenna 10 shown in fig. 2.

The first reflector 3 is located around the first vibrator 23 in the active vibrator 2 with a gap from the first vibrator 23. Specifically, the distance D between the first reflector 3 and the first vibrator 23 in the Y-axis direction of the first mounting surface 101 is set to₁The included angle between the reflection direction of the electromagnetic wave emitted by the first oscillator 23 by the first reflector 3 and the first mounting surface 101 is

The wavelength of the electromagnetic wave emitted by the first oscillator 23 is lambda₁. In the embodiment of the present application, the Y-axis direction of the first mounting surface 101 is a direction perpendicular to the X-axis on the first mounting surface 101, the positive Y-axis direction is a right-side direction, and the negative Y-axis direction is a left-side direction.

According to the interference principle of electromagnetic waves, the three parameters satisfy the formula

Wherein n is a natural number not equal to 0. As can be seen from the above equation, if the distance D between the first reflector 3 and the first vibrator 23 is large₁Is approximated by λ₁/4, then

The first reflector 3 reflects the electromagnetic wave emitted by the first vibrator 23 to the right side; if the distance D between the first reflector 3 and the first vibrator 23₁Is approximated by λ₁A/2, then

At this time, the first reflector 3 reflects the electromagnetic wave emitted from the first vibrator 23 in the direction perpendicular to the first mounting surface 101. That is, by adjusting the distance D between the first reflector 3 and the first vibrator 23₁Size of (2)The direction of reflection of the electromagnetic wave emitted from the first transducer 23 by the first reflector 3 can be changed. When designing the directional antenna 10, the distance D between the first reflector 3 and the first element 23 can be designed according to practical requirements₁To boost the gain of the directional antenna 10 in a particular direction.

In the present embodiment, the distance D between the first reflector 3 and the first vibrator 23 in the Y-axis direction₁Is approximated by λ₁/4. Specifically, the first reflector 3 is located at an edge region of the first mounting surface 101 and extends in the X-axis direction. The first resonant circuit 31 of the first reflector 3 is located in the first functional layer 11, that is, the first resonant circuit 31 and the active element 2 can be formed in the same process, and an additional process is not needed to form the first resonant circuit 31, so that the production cost of the directional antenna 10 is saved. Moreover, the first resonant circuit 31 is a physical structure located on the first mounting surface 101, and is mounted on the first mounting surface 101 without additionally adopting a welding process, so that parasitic effects generated by welding and other processes are effectively avoided. In other embodiments, the first resonant circuit may also be formed by a connection of electronic components. For example, the first capacitive element may be an electronic component such as a capacitor that functions as a capacitor, and the first inductive element may be an electronic component such as an inductor that functions as an inductor. As long as the equivalent electrical length of the first reflector is equal to or slightly greater than one-half of the wavelength of the first frequency band, the electromagnetic wave emitted by the first oscillator can be reflected.

Referring to fig. 5, fig. 5 is a detailed structural diagram of the first resonant circuit 31 in the first reflector 3 shown in fig. 2.

The first capacitive element 311 and the first inductive element 312 of the first resonant circuit 31 are physical structures located on the first mounting surface 101. In this embodiment, the first capacitive element 311 includes two metal blocks 3111 disposed at intervals and a gap 3112 between the two metal blocks 3111. Specifically, the length directions of the two metal blocks 3111 are parallel to the X-axis direction, and the slot 3112 is a linear slot extending along the Y-axis direction, so as to reduce the size of the first capacitive element 311 along the Y-axis direction, reduce the size of the first resonant circuit 31 along the Y-axis direction, and further reduce the size of the first reflector 3 along the Y-axis direction. As shown in fig. 6A to 6E, the first capacitive part 311 may include three or more metal blocks 3111 and a gap 3112 between the metal blocks 3111, and the shape of the gap 3112 includes, but is not limited to, a straight line, a broken line, a curved line, and the like.

The first sensing element 312 is located at the left side of the first capacitive element 311, and a gap exists between the first sensing element and the first capacitive element 311. The first sensing member 312 includes a wavy metal wire. In this embodiment, the length direction of the first sensing element 312 is parallel to the X-axis direction, so as to reduce the dimension of the first sensing element 312 along the Y-axis direction, reduce the dimension of the first resonant circuit 31 along the Y-axis direction, and further reduce the dimension of the first reflector 3 along the Y-axis direction. Specifically, the first sensing element 312 is disposed opposite to the first capacitive element 311, and the dimension of the first sensing element 312 and the dimension of the first capacitive element 311 along the X-axis direction are the same, that is, the dimension L of the first resonant circuit 31 along the X-axis direction₃₁Equal to the dimension of the first inductive element 312 or the first capacitive element 311 along the X-axis direction. The waveforms of the metal wires included in the first sensing member 312 include, but are not limited to, any waveforms such as rectangular waveforms or sinusoidal waveforms, as shown in fig. 7A to 7D. In other embodiments, the first sensing element and the first capacitive element may not be disposed opposite to each other, and the positional relationship between the first sensing element and the first capacitive element is not particularly limited in this application as long as the first sensing element is connected in parallel with the first capacitive element.

The first resonant circuit 31 further comprises a first coupling member 313 coupled between the first inductive element 312 and the first capacitive element 311. In this embodiment, there are two first connection elements 313, and the two first connection elements 313 are respectively connected to two ends of the first capacitive element 311 and the first inductive element 312, and are integrally formed with the first capacitive element 31 and the first inductive element 32, so that the first capacitive element 311 and the first inductive element 312 are connected in parallel through the first connection elements 313. Specifically, one first connection member 313 is connected to one metal block 3111 of the first capacitive member 311 and one end of the first inductive member 312, and the other first connection member 313 is connected to the other metal block 3111 of the first capacitive member 311 and the other end of the first inductive member 312. In other embodiments, the number of the first connecting elements may also be two or more, where the two or more first connecting elements are respectively connected to two ends of the first capacitive element and the first inductive element, so that the first capacitive element and the first inductive element are connected in parallel, and the number of the first connecting elements is not specifically limited in this application.

According to the principle of resonant circuit, if the capacitance of the first capacitive element 311 is C and the inductance of the first inductive element 312 is L, the resonant frequency of the first resonant circuit 31 is expressed as

Since the resonance frequency of the first resonance circuit 31 is located in the second frequency band, the resonance frequency of the first resonance circuit 31 is far from the first frequency band. When the electromagnetic wave with the frequency in the first frequency band is transmitted to the first reflector 3, since the resonant frequency of the first resonant circuit 31 is far away from the first frequency band, the first resonant circuit 31 does not resonate and is in a low-resistance state, and the current generated by the electromagnetic wave with the frequency in the first frequency band on the first reflector 3 can flow through the first resonant circuit 31 in the low-resistance state, and at this time, the first resonant circuit 31 is similar to a conductor. When the electromagnetic wave with the frequency in the second frequency band is transmitted to the first reflector 3, since the resonant frequency of the first resonant circuit 31 is in the second frequency band, the first resonant circuit 31 resonates to be in a high-impedance state, and the current generated by the electromagnetic wave with the frequency in the second frequency band on the first reflector 3 cannot flow through the first resonant circuit 31 in the high-impedance state, and at this time, the first resonant circuit 31 is similar to an insulator.

Referring to fig. 8 and 9, fig. 8 is a schematic structural diagram of a simulation design using the first resonant circuit 31 shown in fig. 5 as a transmission line. Fig. 9 is a graph of a two-port S-parameter obtained after a simulation test of the structure shown in fig. 8. In the structure shown in fig. 9, the resonant frequency of the first resonant circuit 31 is described as being between 5.15GHz and 5.85 GHz.

The transmission line comprises an input end 200, and the input end 200 is used for inputting simulation electromagnetic signals with the frequency of 2 GHz-6.5 GHz to the transmission line. A reflection receiving end 300 is disposed near the input end 200 for receiving the simulated electromagnetic signal reflected by the first resonant circuit 31. The other end of the transmission line opposite to the input end 200 is provided with a transmission receiving end 400 for receiving the simulated electromagnetic signal passing through the first resonant circuit 31. As can be seen from fig. 8, in the vicinity of the frequency point of 2.4GHz, the first resonant circuit 31 has small reflection power and large transmission power for the electromagnetic signal, that is, the reflection receiving terminal 300 receives a small amount of the simulated electromagnetic signal and the transmission receiving terminal 400 receives a large amount of the simulated electromagnetic signal, which indicates that the simulated electromagnetic signal input from the input terminal 200 can pass through the first resonant circuit 31 to reach the transmission receiving terminal 400, that is, the first resonant circuit 31 is in a low-resistance state in the vicinity of 2.4 GHz. In the frequency band of 5.15GHz to 5.85GHz, the reflection power of the first resonant circuit 31 to the simulated electromagnetic signal is large and the transmission power is small, that is, the simulated electromagnetic signal received by the reflection receiving end 300 is large and the simulated electromagnetic signal received by the transmission receiving end 400 is small, which indicates that the electromagnetic signal input from the input end 200 cannot pass through the first resonant circuit 31 to reach the transmission receiving end 400 at this time, but the electromagnetic signal is reflected by the substantially omnidirectional reflection receiving end 300, that is, the first resonant circuit 31 is in a high impedance state in the frequency band of 5.15GHz to 5.85 GHz.

That is, when the operating frequency band of the first oscillator 23 is about 2.4GHz and the operating frequency band of the second oscillator 22 is about 5.15GHz to 5.85GHz, if the electromagnetic wave emitted from the first oscillator 23 is transmitted to the first reflector 3, the first resonant circuit 31 is in a low-impedance state and is approximately a conductor because the resonant frequency of the first resonant circuit 31 is within 5.15GHz to 5.85 GHz. When the electromagnetic wave emitted from the second oscillator 22 is transmitted to the first reflector 3, the first resonant circuit 31 resonates in a high impedance state, and is approximated to an insulator.

Referring back to fig. 2, the first reflector 3 further includes a control switch 32, and the control switch 32 is connected in series with the first resonant circuit 31 and electrically connected between the first resonant circuit 31 and the conductive layer 41. Specifically, the control switch 32 is disposed on the supporting surface 401 to control a conduction state between the first resonant circuit 31 and the conductive layer 41, that is, to control a conduction state between the first reflector 3 and the conductive layer 41. Wherein the mechanical length of the control switch 32 along the X-axis direction is L₃₂. In one embodiment, control switch 32 is a PIN diode. In other embodiments, the control switch may also be usedThe switch is a Micro Electro Mechanical System (MEMS) switch, a photoelectric switch, or the like that can switch the on/off state.

In the present embodiment, the first reflector 3 is composed of a first resonance circuit 31 and a control switch 32. Mechanical length L of the first reflector 3₃Equal to the mechanical length L of the first resonant circuit 31₃₁And the mechanical length L of the control switch 32₃₂Sum, i.e. L₃Is equal to L₃₁+L₃₂. In particular, the sum of the electrical length of the first resonant circuit 31 and the electrical length of the control switch 32 is equal to or slightly greater than one quarter of the wavelength of said first frequency band, i.e. L₃₁+L₃₂Is equal to or slightly greater than λ₁/4, i.e. L₃Is equal to or slightly greater than λ₁And/4, the electrical length of the mirror image of the first reflector 3 in the conductive layer 41 is also equal to or slightly greater than one quarter of the wavelength of the first frequency band. Furthermore, the electrical length of the control switch 32 is less than a quarter of the wavelength of said second frequency band, i.e. L₃₂Less than λ₂And/4, and the equivalent electrical length of the control switch 32 is less than one-half of the wavelength of the second frequency band.

When the control switch 32 is closed, the first resonant circuit 31 is electrically connected to the conductive layer 41, i.e. the first reflector 3 is in a conductive state with the conductive layer 41, and the equivalent electrical length of the first reflector 3 is equal to the sum of the electrical lengths of the first reflector 3 and the mirror image of the first reflector 3 on the conductive layer 41, i.e. the equivalent electrical length of the first reflector 3 is equal to twice the electrical length of the first reflector 3. If the electromagnetic wave emitted by the first oscillator 23 is transmitted to the first reflector 3, the first resonant circuit 31 is approximately a conductor, an induced current generated on the first reflector 3 by the electromagnetic wave with the frequency in the first frequency band can flow between the first resonant circuit 31 and the control switch 32, and both the electrical length of the first reflector 3 and the electrical length of the mirror image of the first reflector 3 on the conductive layer 41 are equal to or slightly greater than a quarter of the wavelength of the first frequency band. Since the first reflector 3 is electrically connected to the mirror image of the first reflector 3 on the conductive layer 41, the equivalent electrical length of the first reflector 3 is equal to or slightly greater than one-half of the wavelength of the first frequency band, and the first reflector 3 reflects the electromagnetic wave emitted by the first oscillator 23. If the electromagnetic wave emitted by the second oscillator 21 is transmitted to the first reflector 3, the first resonant circuit 31 is approximately an insulator, and the electromagnetic wave with the frequency in the second frequency band can only generate an induced current on the control switch 32. Since the electrical length of the control switch 32 is less than one quarter of the wavelength of the second frequency band, that is, the equivalent electrical length of the control switch 32 is less than one half of the wavelength of the second frequency band, the first reflector 3 does not reflect the electromagnetic wave emitted by the second oscillator 22, so that the first reflector 3 is transparent to the electromagnetic wave emitted by the second oscillator 22.

When the control switch 32 is turned off, the first resonant circuit 31 is disconnected from the conductive layer 41, i.e., the first reflector 3 is in an off state with respect to the conductive layer 41. If the electromagnetic wave emitted by the first oscillator 23 is transmitted to the first reflector 3, the electrical length of the first reflector 3 is equal to or slightly greater than one quarter of the wavelength of the first frequency band, and the first reflector 3 does not reflect the electromagnetic wave emitted by the first oscillator 23 because the first reflector 3 and the first reflector 3 are separated from each other in a mirror image on the conductive layer 41. If the electromagnetic wave emitted from the second oscillator 22 is transmitted to the first reflector 3, the first resonant circuit 31 is similar to an insulator, and only the control switch 32 in the first reflector 3 generates an induced current. Since the electrical length of the control switch 32 is less than a quarter of the wavelength of the second frequency band, and the control switch 32 are disconnected in a mirror image on the conductive layer 41, the first reflector 3 does not reflect the electromagnetic wave emitted by the second oscillator 22, so that the first reflector 3 is transparent to the electromagnetic wave emitted by the second oscillator 22.

Therefore, when the directional antenna 10 shown in this embodiment works, the on/off of the first reflector 3 and the conductive layer 41 can be controlled according to specific requirements to control whether the first reflector 3 reflects the electromagnetic wave emitted by the first element 23, and determine whether the directional antenna 10 generates an omnidirectional beam or a directional beam in the first frequency band, without affecting the generation of the omnidirectional beam by the directional antenna 10 in the second frequency band.

In this embodiment, there are two first reflectors 3, and the two first reflectors 3 are respectively located on the left and right sides of the active oscillator 2 and are connected to the first oscillator 23 distance D between₁Are all approximate to lambda₁/4. When the control switch 32 of the first reflector 3 on the left side is closed and the electromagnetic wave emitted by the first oscillator 23 is transmitted to the first reflector 3 on the left side, the electromagnetic wave sensed by the first reflector 3 on the left side and the electromagnetic wave emitted by the first oscillator 23 are constructively interfered and strengthened on the right side of the first oscillator 23 and are destructively interfered and weakened on the left side of the first oscillator 23, that is, the electromagnetic wave emitted by the first oscillator 23 is reflected to the right side by the first reflector 3 on the left side, and at this time, the directional antenna 10 generates a directional beam to the right in the first frequency band; when the control switch 32 of the first reflector 3 on the right side is closed, and the electromagnetic wave emitted by the first oscillator 23 is transmitted to the first reflector 3 on the right side, the electromagnetic wave induced by the first reflector 3 on the right side and the electromagnetic wave emitted by the first oscillator 23 are constructively interfered and strengthened on the left side of the first oscillator 23, and are destructively interfered and weakened on the right side of the first oscillator 23, that is, the electromagnetic wave emitted by the first oscillator 23 is reflected to the left side by the first reflector 3 on the right side, and at this time, the directional antenna 10 generates a directional beam to the left in the first frequency band. Therefore, when the directional antenna 10 shown in this embodiment works, the on-off of the two first reflectors 3 and the conductive layer 41 can be controlled according to specific requirements, so as to determine the specific direction of the directional beam generated by the directional antenna 10 in the first frequency band.

Please refer to fig. 10A and 10B. Fig. 10A is a beam pattern of the directional antenna 10 shown in fig. 2 at 2.4 GHz. Fig. 10B is a beam pattern of the directional antenna 10 shown in fig. 2 at 5 GHz. The first frequency band is 2.4GHz, and the second frequency band is 5.15 GHz-5.85 GHz.

When the control switch 32 of the right first reflector 3 is closed, that is, in the process of conducting the right first reflector 3 and the conductive layer 41 for operation, when the first oscillator 23 transmits electromagnetic waves with a frequency of 2.4GHz to the right first reflector 3, the right first reflector 3 reflects the electromagnetic waves with a frequency of 2.4GHz to the left, and at this time, the directional antenna 10 generates a leftward directional beam at 2.4GHz, thereby increasing the gain of the directional antenna 10 on the left; when the control switch 32 of the left first reflector 3 is closed, that is, in the process of conducting the first reflector 3 on the left of the active oscillator 2 and the conductive layer 41 for operation, when the electromagnetic wave with the frequency of 2.4GHz is transmitted to the left first reflector 3, the left first reflector 3 reflects the electromagnetic wave with the frequency of 2.4GHz to the right, and at this time, the directional antenna 10 generates a rightward directional beam at 2.4GHz, so that the gain of the directional antenna 10 on the right is increased; when the first reflectors 3 on the left and right sides of the active vibrator 2 are electrically connected to the conductive layer 41, both the first reflectors 3 are transparent to electromagnetic waves having a frequency of 5GHz, and the directional antenna 10 generates an omnidirectional beam at 5 GHz.

In this embodiment, the mounting plate 1 is disposed on the bearing surface 401 and perpendicular to the floor 4. In one embodiment, the conductive layer 41 disposed on the carrying surface 401 is made of a metal material, i.e., the conductive layer 41 is a metal layer. In other embodiments, the material of the conductive layer may be another conductor, or the material of the floor may be the same as the material of the conductive layer, and the floor and the conductive layer may be integrally formed metal plates, so as to simplify the production process of the directional antenna and reduce the production cost of the directional antenna. In other embodiments, the mounting plate may not be perpendicular to the floor, that is, an included angle between the first mounting surface and the bearing surface may be less than 90 degrees, which is not specifically limited in the present application.

The conductive layer 41 reflects the active oscillator 2 and the first reflector 3 in a mirror image manner, and according to the mirror image principle (mirror image principle) of electromagnetic waves, the equivalent electrical length of the first oscillator 23 of the active oscillator 2 is equal to the sum of the electrical lengths of the first oscillator 23 and the mirror image of the first oscillator 23 on the conductive layer 41, that is, the equivalent electrical length of the first oscillator 23 is equal to twice the electrical length of the first oscillator 23, that is, the electrical length of the first oscillator 23 is equal to one quarter of the wavelength of the first frequency band, and thus the electromagnetic waves with the frequency in the first frequency band can be transmitted or received. Similarly, as long as the electrical length of the second oscillator 22 of the active oscillator 2 is equal to one fourth of the wavelength of the second frequency band, the electromagnetic wave with the frequency in the second frequency band can be transmitted or received, and as long as the electrical length of the first reflector 3 is equal to or slightly greater than one fourth of the wavelength of the first frequency band, the first reflector 3 can reflect the electromagnetic wave transmitted by the first oscillator 23.

That is to say, the directional antenna 10 shown in this embodiment mirrors the active element 2 and the first reflector 3 by using the conductive layer 41, so that the equivalent electrical length of the active element 2 and the first reflector 3 is equal to twice the electrical length of the active element 2 and the first reflector 3, which is equivalent to reducing the mechanical length of the active element 2 and the first reflector 3 by half, and reducing the size of the directional antenna 10, thereby not only saving the manufacturing cost of the directional antenna 10, but also improving the structural compactness of the directional antenna 10, and being beneficial to the miniaturization design of the directional antenna 10. In other embodiments, the mounting plate may not be perpendicular to the floor, that is, an included angle between the bearing surface and the first mounting surface may be smaller than 90 degrees, as long as the electrical lengths of the active vibrator and the first reflector are adaptively adjusted so that the active vibrator and the first reflector can normally operate.

In other embodiments, if the ground plane is not provided with a conductive layer for mirroring the active element and the first reflector, the directional antenna should complement the electrical lengths of the active element and the first reflector with an actual conductor structure so that the electrical lengths of the active element and the first reflector are equal to an equivalent electrical length.

When the directional antenna 10 shown in this embodiment operates, the rf module 30 sends an electromagnetic signal to the feeding point 21 through the feed line, and the active element 2 receives the electromagnetic signal and then radiates an electromagnetic wave to the outside. In the process that the control switch 32 of the first reflector 3 on the left side is closed to conduct the first reflector 3 and the conductive layer 41, when the electromagnetic wave emitted by the first oscillator 23 in the active oscillator 2 is transmitted to the first reflector 3, the first resonant circuit 31 of the first reflector 3 is in a conducting state without resonance, at this time, the equivalent electrical length of the first reflector 3 is equal to or slightly greater than one half of the wavelength of the first frequency band, the first reflector 3 resonates to reflect the electromagnetic wave emitted by the first oscillator 23, and the electromagnetic wave emitted by the first oscillator 23 is directionally reflected to the right, so that the gain of the directional antenna 10 on the right side is enhanced, and the communication quality is improved; when the electromagnetic wave emitted by the second vibrator 22 in the active vibrator 2 propagates to the first reflector 3, the first resonant circuit 31 resonates and is in an off state, and the flow of the induced current on the first reflector 3 is blocked, and at this time, the electromagnetic wave emitted by the second vibrator 22 can pass through the first reflector 3 and keep normal propagation, that is, the electromagnetic wave emitted by the second vibrator 22 is not distorted by the first reflector 3. The operation of the right-hand first reflector 3 is substantially the same as that of the left-hand first reflector 3, and the only difference is that the right-hand first reflector 3 reflects the electromagnetic wave emitted by the first vibrator 23 to the left directionally, which will not be described in detail herein. That is, in the directional antenna 10 according to the embodiment of the present application, the first reflector 3 can reflect the electromagnetic wave emitted from the first element 23, and can maintain transparency to the electromagnetic wave emitted from the second element 22, so that the electromagnetic wave emitted from the second element 22 is not distorted. Since the first reflector 3 can selectively reflect the electromagnetic wave with the frequency in the first frequency band, the beam modes of the directional antenna 10 in the first frequency band and the second frequency band are independent of each other, and the directional antenna can operate in the dual frequency bands according to the independent directional modes.

Please refer to fig. 11 and 12. Fig. 11 is a schematic structural diagram of a second directional antenna 10 according to an embodiment of the present application. Fig. 12 is a schematic cross-sectional view of the directional antenna 10 shown in fig. 11 along the direction B-B. The directional antenna 10 corresponds to the directional antenna 10 in the communication device 100 shown in fig. 1.

The difference between the directional antenna 10 of the present embodiment and the directional antenna 10 of the previous embodiment is that the first reflector 3 further includes a conductive member 33, the conductive member 33 is connected in series with the first resonant circuit 31, the first resonant circuit 31 is connected between the conductive member 2 and the control switch 32, and the equivalent electrical length of the first reflector 3 minus the equivalent electrical length of the conductive member 33 is less than one-half of the wavelength of the first frequency band. Specifically, the conductive element 33 is located in the first functional layer 11, that is, the conductive element 33 may also be formed in the same process as the active element 2, and an additional process is not required to form the conductive element 33, so that the production cost of the directional antenna 10 is saved. In other embodiments, the conductive member may also be connected between the first resonant circuit and the control switch, which is not specifically limited in this application.

In one embodiment, the conductive member 33 is connected to the first inductive element 312 of the first resonant circuit 31, i.e. the first inductive element 312 is connected between the conductive member 33 and the control switch 32. The conductive member 33 extends along the X-axis direction, and the mechanical length of the conductive member 33 along the X-axis direction is L₃₃. In other embodiments, the first capacitive element may also be connected between the conductive element and the control switch, which is not specifically limited in this embodiment.

In the present embodiment, the first reflector 3 is composed of a first resonance circuit 31, a control switch 32, and a conductive member 33. Mechanical length L of the first reflector 3₃Equal to the mechanical length L of the first resonant circuit 31₃₁And the mechanical length L of the control switch 32₃₁And mechanical length L of conductive member 33₃₃Sum, i.e. L₃Is equal to L₃₁+L₃₂+L₃₃. Specifically, the sum of the electrical length of the first resonant circuit 31, the electrical length of the control switch 32 and the electrical length of the conductive member 33 is equal to or slightly greater than one quarter of the wavelength of the first frequency band, i.e., L₃₁+L₃₂+L₃₃Is equal to or slightly greater than λ₁/4, i.e. L₃Is equal to or slightly greater than λ₁/4. Furthermore, the electrical length of the control switch 32 and the electrical length of the conductive member 33 are both less than one quarter of the wavelength of said second frequency band, i.e. L₃₂And L₃₃Are all less than lambda₂And/4, the equivalent electrical length of the control switch 32 and the equivalent electrical length of the conductive member 33 are both less than one half of the wavelength of the second frequency band, so as to avoid the control switch 32 and the conductive member 33 from reflecting the electromagnetic wave emitted by the second oscillator 22, and thus the first reflector 3 is transparent to the electromagnetic wave emitted by the second oscillator 22.

That is, when the sum of the equivalent electrical lengths of the first resonance circuit 31 and the control switch 32 is smaller than the wavelength λ of the first band₁When the sum of the electrical length of the first resonant circuit 31 and the electrical length of the control switch 32 is less than one-fourth of the wavelength of the first frequency band, the length of the first reflector 3 in the X-axis direction, i.e. the mechanical length of the first reflector 3, can be increased by adding the conductive member 33, which is equivalent to thatThe electrical length of the first reflector 3 is increased, and the equivalent electrical length of the first reflector 3 is complemented, so that the equivalent electrical length of the first reflector 3 is equal to or slightly greater than one half of the wavelength of the first frequency band, and the electromagnetic wave emitted by the first oscillator 23 can be reflected, and the directional reflection of the electromagnetic wave emitted by the first oscillator 23 is realized.

In other embodiments, the number of the conductive members may be multiple, and a part of the conductive members is connected to the first capacitive member, and another part of the conductive members is connected to the first inductive member.

Please refer to fig. 13 and 14. Fig. 13 is a schematic structural diagram of a third directional antenna 10 according to an embodiment of the present application. Fig. 14 is a schematic cross-sectional view of the directional antenna 10 shown in fig. 13 along the direction C-C. The directional antenna 10 corresponds to the directional antenna 10 in the communication device 100 shown in fig. 1.

The directional antenna 10 shown in this embodiment is different from the directional antenna 10 shown in the two embodiments in that the active element 2 further includes a third element (not shown), and an operating frequency band of the third element is a third frequency band. The first reflector 3 further comprises a second resonant circuit 34 in series with the first resonant circuit 31, the second resonant circuit 34 comprising a second capacitive element 341 and a second inductive element 342 connected in parallel, the resonant frequency of the second resonant circuit 34 being in said third frequency band.

In this embodiment, there are two third oscillators, and the two third oscillators are symmetrically distributed on two sides of the first oscillator 23, and a gap is formed between the two third oscillators and the first oscillator 23. Specifically, the third oscillator extends along the X-axis direction, and an equivalent electrical length of the third oscillator is equal to one half of a wavelength of the third frequency band, so as to transmit and receive electromagnetic waves with frequencies in the third frequency band. The sum of the electrical lengths of the mirror images of the third oscillator and the third oscillator on the conductive layer 41 is equal to the equivalent electrical length of the third oscillator, that is, twice the electrical length of the third oscillator is equal to the equivalent electrical length of the third oscillator, that is, the electrical length of the third oscillator is equal to one quarter of the wavelength of the third frequency band. In one embodiment, the minimum frequency in the third frequency band is greater than the maximum frequency in the second frequency band, that is, the operating frequency band of the third oscillator is higher than the operating frequency bands of the second oscillator and the first oscillator. In other embodiments, the maximum frequency in the third frequency band may also be smaller than the minimum frequency in the second frequency band, that is, the operating frequency band of the third oscillator is lower than the operating frequency band of the second oscillator, which is not specifically limited in this embodiment.

The first resonant circuit 31 is connected between the control switch 32 and the second resonant circuit 34. The second resonant circuit 34 extends in the X-axis direction to reduce the size of the first reflector 3 in the Y-axis direction, that is, to reduce the lateral size of the first reflector 3, thereby improving the compactness of the directional antenna 10. Specifically, the second resonant circuit 34 is located in the first functional layer 11 and can be formed in the same process as the active element 2, and an additional process is not required to form the second resonant circuit 34, so that the production cost of the directional antenna 10 is saved. Moreover, the second resonant circuit 34 is a physical structure located on the first mounting surface 101, and is mounted on the first mounting surface 101 without adopting an additional welding process, so that parasitic effects generated by welding and other processes are effectively avoided. In other embodiments, the second resonant circuit may also be connected between the first resonant circuit and the control switch, and the second resonant circuit may also be formed by connecting electronic components. For example, the second capacitive element of the second resonant circuit may be an electronic component such as a capacitor that functions as a capacitor, and the second inductive element may be an electronic component such as an inductor that functions as an inductor. As long as the equivalent electrical length of the first reflector is equal to or slightly greater than one-half of the wavelength of the first frequency band, the electromagnetic wave generated by the first oscillator can be reflected.

The second capacitive element 341 and the second inductive element 342 of the second resonant circuit 34 are physical structures located on the first mounting surface 101. The second capacitive element 341 is similar in structure to the first capacitive element 311. In this embodiment, the second capacitive element 341 includes two metal blocks disposed at intervals and a gap between the two metal blocks. Specifically, the length directions of the two metal blocks are parallel to the X-axis direction, and the slits are linear slits extending along the Y-axis direction, so as to reduce the size of the second capacitive element 341 along the Y-axis direction, further reduce the size of the second resonant circuit 34 along the Y-axis direction, and further reduce the size of the first reflector 3 along the Y-axis direction. In other embodiments, the second capacitive element may also include three or more metal blocks and a gap between the metal blocks, and the shape of the gap includes, but is not limited to, a straight line, a broken line, a curved line, and the like.

The second sensing element 342 is located at the right side of the second capacitive element 341, and a gap exists between the second sensing element and the second capacitive element 341. The second sensing member 342 is similar in structure to the first sensing member 312, and the second sensing member 342 includes a corrugated metal wire. In this embodiment, the length direction of the second inductive element 342 is parallel to the X-axis direction, so as to reduce the dimension of the second inductive element 342 along the Y-axis direction, reduce the dimension of the second resonant circuit 34 along the Y-axis direction, and further reduce the dimension of the first reflector 3 along the Y-axis direction. Specifically, the second sensing element 342 and the second capacitive element 341 are disposed opposite to each other, and the dimension of the second sensing element 342 and the dimension of the second capacitive element 341 along the X-axis direction are the same, that is, the dimension L of the second resonant circuit 34 along the X-axis direction₃₄Equal to the dimension of the second inductive element 342 or the second capacitive element 341 along the X-axis direction. The waveform of the metal wire included in the second sensing member 342 includes, but is not limited to, any waveform such as a rectangular waveform or a sinusoidal waveform. In other embodiments, the second sensing element and the second capacitive element may not be disposed opposite to each other, and the application does not specifically limit the positional relationship between the second sensing element and the second capacitive element as long as the second sensing element is connected in parallel with the second capacitive element.

The second resonant circuit 34 further comprises a second connection 343 coupled between the second inductive element 342 and the second capacitive element 341. In this embodiment, there are two second connecting members 343, and the two second connecting members 343 are respectively connected to two ends of the second capacitive element 341 and the second inductive element 342 and are integrally formed with the second capacitive element 341 and the second inductive element 342, so that the second capacitive element 341 and the second inductive element 342 are connected in parallel through the second connecting members 343. Specifically, one second connecting part 343 is connected to one metal block 3411 of the second capacitive part 341 and one end of the second inductive part 342, and the other second connecting part 343 is connected to the other metal block 3411 of the second capacitive part 341 and the other end of the second inductive part 342. In other embodiments, the number of the second connecting members is not particularly limited as long as the second capacitive element and the second inductive element can be connected in parallel.

Since the resonance frequency of the second resonant circuit 34 is within the third frequency band, the resonance frequency of the second resonant circuit 34 is far from the first frequency band and the second frequency band. When the electromagnetic wave with the frequency in the first frequency band or the second frequency band is transmitted to the first reflector 3, since the resonant frequency of the second resonant circuit 34 is far away from the first frequency band and the second frequency band, the second resonant circuit 34 does not resonate and is in a low-resistance state, and the current generated by the electromagnetic wave with the frequency in the first frequency band or the second frequency band on the first reflector 3 can flow through the second resonant circuit 34 in the low-resistance state, and at this time, the second resonant circuit 34 is approximate to a conductor. When the electromagnetic wave with the frequency in the third frequency band is transmitted to the first reflector 3, since the resonant frequency of the second resonant circuit 34 is in the third frequency band, the second resonant circuit 34 resonates and is in a high impedance state, and the current generated by the electromagnetic wave with the frequency in the third frequency band on the first reflector 3 cannot flow through the second resonant circuit 34 in the high impedance state, and at this time, the first resonant circuit 31 is similar to an insulator.

In the directional antenna 10 shown in this embodiment, because the resonant frequencies of the first resonant circuit 31 and the second resonant circuit 34 are different, the capacitance values of the first capacitive element 311 and the second capacitive element 341 may be the same or different, that is, the widths of the slot of the first capacitive element 311 and the slot of the second capacitive element 341 may be the same or different. Similarly, the inductance values of the first inductive element 312 and the second inductive element 342 may be the same or different, that is, the widths of the metal line of the first inductive element 312 and the metal line of the second inductive element 342 may be the same or different, and this is not particularly limited in this application as long as the resonant frequencies of the first resonant circuit 31 and the second resonant circuit 34 are different. In other embodiments, the active element may include more than three elements having different operating frequency bands, and the first reflector may also include more than two resonant circuits connected in series, where a resonant frequency of each resonant circuit is within the operating frequency band of one element, so that the first reflector may selectively reflect electromagnetic waves of a specific frequency band of the more than three frequency bands, so that the directional antenna may operate in the more than three frequency bands according to independent directional modes, and beam modes of the more than three frequency bands are independent of each other.

In the present embodiment, the first reflector 3 is composed of a first resonance circuit 31, a control switch 32, and a second resonance circuit 34. Mechanical length L of the first reflector 3₃Equal to the mechanical length L of the first resonant circuit 31₃₁And the mechanical length L of the control switch 32₃₁And the mechanical length L of the second resonant circuit 34₃₄Sum, i.e. L₃Is equal to L₃₁+L₃₂+L₃₄. In particular, the sum of the electrical length of the first resonant circuit 31, the electrical length of the control switch 32 and the electrical length of the second resonant circuit 34 is equal to or slightly greater than one quarter of the wavelength of said first frequency band, i.e. L₃₁+L₃₂+L₃₄Is equal to or slightly greater than λ₁/4, i.e. L₃Is equal to or slightly greater than λ₁And/4, the electrical length of the mirror image of the first reflector 3 in the conductive layer 41 is also equal to or slightly greater than one quarter of the wavelength of the first frequency band. Furthermore, the electrical length of the control switch 32 and the second resonance circuit 34 are each less than a quarter of the wavelength of said second frequency band, i.e. L₃₂And L₃₄Are all less than lambda₂And/4, and the equivalent electrical lengths of the control switch 32 and the second resonant circuit 34 are each less than one-half of the wavelength of said second frequency band. Furthermore, the sum of the electrical lengths of the first resonant circuit 34 and the control switch 32 is less than a quarter of the wavelength of said third frequency band, i.e. L₃₁+L₃₂Less than λ₃/4 and the equivalent electrical length of the first resonant circuit 34 and the control switch 32 is less than two-thirds the wavelength of said third bandOne of them.

When the electromagnetic wave emitted by the first oscillator 23 is transmitted to the left first reflector 3 in the process that the control switch 32 of the left first reflector 3 is closed to conduct the first reflector 3 with the conductive layer 41, because the first resonant circuit 31 and the second resonant circuit 34 are both approximate conductors, the induced current generated by the electromagnetic wave with the frequency in the first frequency band on the left first reflector 3 can flow among the first resonant circuit 31, the control switch 32 and the second resonant circuit 34, and the electrical length L of the left first reflector 3₃/λ₁And the electrical length of the mirror image of the first reflector 3 on the left on the conductive layer 41 are both equal to or slightly greater than one-half of the wavelength of said first frequency band. Since the first reflector 3 on the left side is connected with the first reflector 3 on the left side in a mirror image manner on the conductive layer 41, the equivalent electrical length of the first reflector 3 on the left side is equal to or slightly greater than one half of the wavelength of the first frequency band, the first reflector 3 on the left side reflects the electromagnetic wave emitted by the first oscillator 23, the electromagnetic wave emitted by the first oscillator 23 is emitted to the right side, and the directional antenna 10 generates a directional beam to the right in the first frequency band.

When the electromagnetic wave emitted from the second vibrator 22 is transmitted to the first reflector 3 on the left side, the first resonance circuit 31 is approximated to an insulator, and the second resonance circuit 34 is approximated to a conductor. The first resonant circuit 31 will block the induced current generated on the first reflector 3 on the left side by the electromagnetic wave with the frequency in the second frequency band, and the induced current can be generated only on the control switch 32 and the second resonant circuit 34, which is equivalent to dividing the first reflector 3 into two parts, namely the control switch 32 and the second resonant circuit 34. Because the electrical lengths of the control switch 32 and the second resonant circuit 34 are both less than one fourth of the wavelength of the second frequency band, the equivalent electrical lengths of the control switch 32 and the second resonant circuit 34 are both less than one half of the wavelength of the second frequency band, and neither the control switch 32 nor the second resonant circuit 34 reflects the electromagnetic wave emitted by the second element 22, the electromagnetic wave emitted by the second element 22 appears transparent to the first reflector 3 on the left side, and the directional antenna 10 generates an omnidirectional beam in the second frequency band.

When the electromagnetic wave emitted by the third oscillator is transmitted to the first reflector 3 on the left side, the first resonant circuit 31 is approximately a conductor, the second resonant circuit 34 is approximately an insulator, and the second resonant circuit 34 blocks the induced current generated on the first reflector 3 on the left side by the electromagnetic wave with the frequency in the third frequency band, so that the induced current can be generated only on the first resonant circuit 31 and the control switch 32. Since the sum of the electrical lengths of the first resonant circuit 31 and the control switch 32 is less than one fourth of the wavelength of the third frequency band, that is, the sum of the equivalent electrical lengths of the first resonant circuit 31 and the control switch 32 is less than one half of the wavelength of the third frequency band, the first resonant circuit 31 and the control switch 32 do not reflect the electromagnetic wave emitted by the third element, so that the first reflector 3 is transparent to the electromagnetic wave emitted by the third element, and the directional antenna 10 generates an omnidirectional beam in the third frequency band.

The operation of the right-side first reflector 3 is substantially the same as that of the left-side first reflector 3, and the only difference is that the right-side first reflector 3 reflects the electromagnetic wave emitted by the first element 23 to the left, and the directional antenna 10 generates a beam to the left in the first frequency band, which will not be described herein too much. That is, in the directional antenna 10 shown in the present embodiment, the first reflector 3 can reflect the electromagnetic wave emitted from the first oscillator 23, and does not generate strong interference such as reflection and scattering on the electromagnetic wave emitted from the second oscillator 21 and the third oscillator, and does not distort the electromagnetic wave emitted from the second oscillator 21 and the third oscillator. Since the first reflector 3 can selectively reflect the electromagnetic waves of a specific frequency band of the three frequency bands, the beam modes of the directional antenna 10 in the first frequency band, the second frequency band and the third frequency band are independent of each other, and the directional antenna can operate in the three frequency bands according to the independent directional modes.

Please refer to fig. 15 and fig. 16. Fig. 15 is a schematic structural diagram of a fourth directional antenna 10 according to an embodiment of the present application. Fig. 16 is a schematic cross-sectional view of the directional antenna 10 shown in fig. 15 along the direction E-E. The directional antenna 10 corresponds to the directional antenna 10 in the communication device 100 shown in fig. 1.

The directional antenna 10 of the present embodiment differs from the directional antenna 10 of the third embodiment in that the first reflector 3 further comprises a conductive member 33, and the conductive member 33 is connected in series with the first resonant circuit 31 and the second resonant circuit 34, i.e. the first resonant circuit 31 and the second resonant circuit 34 are connected in series through the conductive member 33. In other embodiments, the conductive member may also be connected between the first resonant circuit and the control switch, which is not specifically limited in this application.

In one embodiment, the conductive member 33 is connected between the first sensing member 312 and the second sensing member 342. The dimension of the conductive member 33 along the X-axis direction is L₃₃. In other embodiments, the conductive member may also be connected between the first capacitive element and the second capacitive element, which is not particularly limited in this embodiment.

In the present embodiment, the first reflector 3 is composed of a first resonance circuit 31, a control switch 32, a conductive member 33, and a second resonance circuit 34. Mechanical length L of the first reflector 3₃Equal to the mechanical length L of the first resonant circuit 31₃₁ Control switch 32 and mechanical length L₃₂Mechanical length L of conductive member 33₃₃And the mechanical length L of the second resonant circuit 34₃₄Sum, i.e. L₃Is equal to L₃₁+L₃₂+L₃₃+L₃₄. Specifically, the sum of the electrical length of the first resonant circuit 31, the electrical length of the control switch 32, the electrical length of the conductive member 33, and the electrical length of the second resonant circuit 34 is equal to or slightly greater than one quarter of the wavelength of the first frequency band, i.e., L₃₁+L₃₂+L₃₃+L₃₄Is equal to or slightly greater than λ₁/4, i.e. L₃Is equal to or slightly greater than λ₁/4. Furthermore, the sum of the electrical length of the control switch 32 and the electrical lengths of the conductive member 33 and the second resonant circuit 34 is less than one quarter of the wavelength of said second frequency band, i.e. L₃And L₃₃+L₃₄Are all less than lambda ₁4, the sum of the equivalent electrical length of the control switch 32 and the equivalent electrical length of the conductive member 33 and the second resonant circuit 34 is less than one half of the wavelength of the second frequency band, so as to avoid the control switch 32, the conductive member 33 and the second resonant circuit 34 from reflecting the second oscillator 22 to generate the electromagnetic waveThe emitted electromagnetic wave, thereby making the first reflector 3 appear transparent to the electromagnetic wave emitted by the second vibrator 22. Furthermore, the sum of the electrical lengths of the first resonant circuit 31, the control switch 32 and the conductive member 33 is less than one quarter of the wavelength of said third frequency band, i.e. L₃₁+L₃₂+L₃₃Less than λ₁And/4, that is, the sum of the equivalent electrical lengths of the first resonant circuit 31, the control switch 32 and the conductive member 33 is less than one half of the wavelength of the third frequency band, so as to prevent the first resonant circuit 31, the control switch 32 and the conductive member 33 from reflecting the electromagnetic wave emitted by the third oscillator, thereby making the first reflector 3 transparent to the electromagnetic wave emitted by the third oscillator.

Please refer to fig. 17 and 18. Fig. 17 is a schematic structural diagram of a fifth directional antenna 10 according to an embodiment of the present application. Fig. 18 is a schematic cross-sectional view of the directional antenna 10 shown in fig. 17 along the F-F direction. The directional antenna 10 corresponds to the directional antenna 10 in the communication device 100 shown in fig. 1.

The directional antenna 10 shown in the embodiment of the present application is different from the directional antenna 10 shown in the above four embodiments in that the mounting board 1 further includes a second mounting surface 102 disposed opposite to the first mounting surface 101, the second mounting surface 102 is provided with a second functional layer 12, the first capacitive element 311 and the first inductive element 312 of the first resonant circuit 31 are respectively located in the first functional layer 11 and the second functional layer 12, and the first capacitive element 311 and the second inductive element 312 are disposed opposite to each other. In other embodiments, the first capacitive element and the first inductive element may both be located within the second functional layer.

In this embodiment, the mounting plate 1 is provided with two first through holes 103, the two first through holes 103 all penetrate through the first mounting surface 101 and the second mounting surface 102, and a gap exists between the two first through holes 103. Specifically, the material of the second functional layer 12 disposed on the second mounting surface 102 is metallic copper, that is, the second functional layer 12 is a copper layer disposed on the second mounting surface 102. In one embodiment, the second functional layer 12 is printed on the second mounting surface 102. In other embodiments, the material of the second functional layer may also be other conductors, and this is not specifically limited in this application.

The first sensitive element 312 and the active vibrator 2 are located in the first functional layer 11, and the first capacitive element 311 is located in the second functional layer 12. In this embodiment, the dimensions of the first sensing element 312 and the first capacitive element 311 in the X-axis direction and the Y-axis direction are the same. The first inductive element 312 is disposed opposite to the first capacitive element 311, that is, the projection of the first inductive element 312 on the second functional layer 12 just covers the first capacitive element 311, that is, the projection of the first capacitive element 311 on the first functional layer 11 just covers the first inductive element 312, so as to further reduce the size of the first resonant circuit 31 along the Y-axis direction, that is, reduce the lateral size of the first resonant circuit 31, further reduce the lateral size of the first reflector 10, and improve the structural compactness of the directional antenna 10.

Referring to fig. 19, fig. 19 is a schematic partial structure diagram of the directional antenna 10 shown in fig. 17.

In this embodiment, the first resonant circuit 31 further includes two first conductive pillars 314, and the two first conductive pillars 314 are respectively filled in the two first through holes 103 to electrically connect the two ends of the first capacitive element 311 and the first inductive element 312, so that the first capacitive element 311 and the first inductive element 312 are connected in parallel. In one embodiment, the material of the first conductive pillar 314 is metal. In other embodiments, the material of the first conductive pillar may be another conductive material, and of course, the first conductive pillar may also be a structure having a conductive function, such as a conductive line, as long as the first capacitive element and the first inductive element can be connected in parallel, which is not particularly limited in this application.

In other embodiments, the mounting board may also be provided with more than two first through holes, the first resonant circuit may also include more than two first conductive pillars, and each first conductive pillar is filled in one first through hole, so that the first capacitive element is connected in parallel to the first inductive element, which is not limited in this application.

Please refer to fig. 20 and 21. Fig. 20 is a schematic structural diagram of a sixth directional antenna 10 according to an embodiment of the present application. Fig. 21 is a schematic cross-sectional view of the directional antenna 10 shown in fig. 20 along the G-G direction. The directional antenna 10 corresponds to the directional antenna 10 in the communication device 100 shown in fig. 1.

The directional antenna 10 shown in the embodiment of the present application is different from the directional antenna 10 shown in the fifth embodiment in that the active element 2 further includes a third element (not shown), and an operating frequency band of the third element is a third frequency band. The first reflector 3 further comprises a second resonant circuit 34 in series with the first resonant circuit 31, the second resonant circuit 34 comprising a second capacitive element 341 and a second inductive element 342 connected in parallel, the resonant frequency of the second resonant circuit 34 being in said third frequency band.

In this embodiment, the first resonant circuit 31 is connected between the control switch 32 and the second resonant circuit 34. The second resonant circuit 34 extends in the X-axis direction to reduce the size of the first reflector 3 in the Y-axis direction, that is, to reduce the lateral size of the first reflector 3, thereby improving the compactness of the directional antenna 10. The second capacitive element 341 and the second inductive element 342 of the second resonant circuit 34 are located within the first functional layer 11 and the second functional layer 12, respectively. In other embodiments, the second capacitive element and the second inductive element may both be located within the second functional layer.

In one embodiment, two second through holes 104 are formed in the mounting plate 1, the two second through holes 104 penetrate through the first mounting surface 101 and the second mounting surface 102, and a gap exists between the two second through holes 104. In particular, the second capacitive element 341 of the second resonant circuit 34 is located within the second functional layer 12 and the second inductive element 342 is located within the first functional layer 11. That is, the first capacitive element 311 and the second capacitive element 341 are located in the second functional layer 12, and the first inductive element 312 and the second inductive element 342 are located in the first functional layer 11. In other embodiments, the first capacitive element and the second capacitive element may be located in the first functional layer and the second functional layer, respectively, and the first inductive element and the second inductive element may be located in the first functional layer and the second functional layer, respectively, which is not particularly limited in this application.

In this embodiment, the dimensions of the second capacitive element 341 are the same as the dimensions of the second inductive element 341 in the X-axis direction and the Y-axis direction. The second capacitive element 341 is disposed opposite to the second inductive element 342, that is, the projection of the second inductive element 342 on the second functional layer 12 just covers the second capacitive element 341, that is, the projection of the second capacitive element 341 on the first functional layer 11 just covers the second inductive element 342, so as to further reduce the size of the second resonant circuit 34 along the Y-axis direction, that is, reduce the lateral size of the second resonant circuit 34, further reduce the lateral size of the antenna 10, improve the structural compactness of the directional antenna 10, and facilitate the miniaturization design of the directional antenna 10.

In this embodiment, the second resonant circuit 34 further includes two second conductive pillars 344, and the two second conductive pillars 344 are respectively filled in the two second through holes 104 to electrically connect two ends of the second capacitive element 341 and the second inductive element 342, so that the second capacitive element 341 and the second inductive element 342 are connected in parallel. In one embodiment, the material of the second conductive pillar 344 is metal. In other embodiments, the material of the second conductive pillar may be another conductive material, but the second conductive pillar may also be a conductive line or other structure having a conductive function, as long as the second capacitive element and the second inductive element can be connected in parallel, and this is not particularly limited in this application.

In other embodiments, the mounting board may also have at least two second through holes, and the second resonant circuit may also include at least two second conductive pillars, where each second conductive pillar fills one second through hole, so that the second capacitive element is connected in parallel to the second inductive element, which is not limited in this application.

Referring to fig. 22, fig. 22 is a schematic structural diagram of a seventh directional antenna 10 according to an embodiment of the present disclosure. The directional antenna 10 corresponds to the directional antenna 10 in the communication device 100 shown in fig. 1.

The directional antenna 10 shown in this embodiment is different from the six directional antennas 10 described above in that the directional antenna 10 further includes a second reflector 5, an equivalent electrical length of the second reflector 5 is equal to or slightly greater than one-half of a wavelength of the second frequency band, and an electromagnetic wave having a frequency in the second frequency band resonates on the second reflector 5. In the present embodiment, the equivalent electrical length of the second reflector 5 is equal to the sum of the electrical lengths of the second reflector 5 and the mirror images of the second reflector 5 in the conductive layer 41, i.e., the equivalent electrical length of the second reflector 5 is equal to twice the electrical length of the second reflector 5. I.e. the electrical length of the second reflector 5 is equal to or slightly larger than a quarter of the wavelength of said second frequency band.

The second reflector 5 is located in the edge area of the first mounting surface 101 and between the active vibrator 2 and the first reflector 3. Specifically, the second reflector 5 extends in the X-axis direction. The second reflector 5 includes a reflecting body 51 and a selection switch 52. The reflection main body 51 is positioned in the first functional layer 11 and can be formed with the active oscillator 2 in the same process, and an additional process is not needed to form the reflection main body 51, so that the manufacturing cost of the directional antenna 10 is saved. Moreover, the reflection body 51 is a physical structure formed on the first mounting surface 101, and the reflection body 51 does not need to be welded on the first mounting surface 101 by adopting a welding process, so that the preparation process of the directional antenna 10 is saved. The selection switch 52 is disposed on the supporting surface 401 and electrically connected between the reflective body 51 and the conductive layer 41 for controlling the conduction state between the reflective body 51 and the conductive layer 41, i.e. controlling the conduction state between the second reflector 5 and the conductive layer 41. In one embodiment, the selection switch 52 is a PIN diode. In other embodiments, the selection switch may also be a MEMS switch or an opto-electronic switch.

When the selection switch 52 is closed, the reflective body 51 is electrically connected to the conductive layer 41, i.e., the second reflector 5 is in a conductive state with the conductive layer 41. If the electromagnetic wave emitted by the second oscillator 22 is transmitted to the second reflector 5, because the second reflector 5 is electrically connected with the second reflector 5 in the mirror image of the conductive layer 41, the equivalent electrical length of the second reflector 5 is equal to or slightly greater than one half of the wavelength of the second frequency band, and the electromagnetic wave induced by the second reflector 5 and the electromagnetic wave emitted by the second oscillator 22 constructively interfere in one direction to be strengthened and destructively interfere in the other direction to be weakened. The second reflector 5 reflects the electromagnetic wave emitted by the second oscillator 22, so that the gain of the directional antenna 10 in the reflection direction is enhanced, and the communication quality is improved.

When the selection switch 52 is turned off, the reflective body 51 is disconnected from the conductive layer 41, i.e., in an off state between the second reflector 5 and the conductive layer 41. When the electromagnetic wave emitted by the second oscillator 22 is transmitted to the second reflector 5, the second reflector 5 does not emit the electromagnetic wave emitted by the second oscillator 22 because the second reflector 5 and the second reflector 5 are separated in the mirror image of the conductive layer 41.

Therefore, in the directional antenna 10 shown in this embodiment, the on/off between the second reflector 5 and the conductive layer 41 can be controlled by the selection switch 52, so that when the directional antenna 10 operates, whether the second reflector 5 reflects the electromagnetic wave emitted by the second element 22 can be controlled according to specific requirements, and whether the directional antenna 10 generates an omnidirectional beam or a directional beam in the second frequency band is determined.

In this embodiment, there are two second reflectors 5, and the two second reflectors 5 are respectively located on the left and right sides of the active oscillator 2 and are radially symmetric with respect to the active oscillator 2. Specifically, the left second reflector 5 is located between the left second oscillator 22 and the left first reflector 3The right second reflector 5 is located between the right second transducer 22 and the right first reflector 3. Distance D between left second reflector 5 and left second transducer 22 along Y-axis direction₂Is approximated by λ₂/4, distance D between right second reflector 5 and right second oscillator 22₂Is approximated by λ₂/4. Wherein λ is₂Is the wavelength of the electromagnetic wave emitted by the second element 22.

In the operation of the directional antenna 10 shown in this embodiment, when the selection switch 52 is turned off, that is, when neither of the second reflectors 5 is in conduction with the conductive layer 41, the directional antenna 10 generates an omnidirectional beam in the second frequency band. When the right second reflector 5 is conducted with the conductive layer 41, the electromagnetic wave induced by the right second reflector 5 and the electromagnetic wave emitted by the right second element 22 constructively interfere with each other at the left side of the right second element 22 to be strengthened, and destructively interfere with each other at the right side of the right second element 22 to be weakened, that is, the right second reflector 5 reflects the electromagnetic wave emitted by the right second element 22 to the left side, and at this time, the directional antenna 10 generates a directional beam to the left in the second frequency band. When the left second reflector 5 is conducted with the conductive layer 41, the electromagnetic wave induced by the left second reflector 5 and the electromagnetic wave emitted by the left second element 22 constructively interfere with each other on the right side of the left second element 22 to be strengthened, and destructively interfere with each other on the left side of the left second element 22 to be weakened, that is, the left second reflector 5 reflects the electromagnetic wave emitted by the left second element 22 to the right, and at this time, the directional antenna 10 generates a directional beam to the right in the second frequency band. At this time, when the second reflectors 5 located on both sides of the active element 2 are electrically connected to the conductive layer 41, the beam of the directional antenna 10 in the first frequency band is not affected. Therefore, when the directional antenna 10 shown in this embodiment works, the on/off of the two second reflectors 5 and the conductive layer 41 can be controlled according to specific requirements, so as to determine the specific direction of the directional beam generated by the directional antenna 10 in the second frequency band.

Claims

1. A directional antenna, comprising an active element and a first reflector;

the active oscillator comprises a first oscillator and a second oscillator, wherein the working frequency band of the first oscillator is a first frequency band, and the working frequency band of the second oscillator is a second frequency band;

the equivalent electrical length of the first reflector is equal to or slightly greater than one-half of the wavelength of the first frequency band;

the first reflector comprises a first resonant circuit, the first resonant circuit comprises a first capacitive element and a first inductive element which are connected in parallel, the resonant frequency of the first resonant circuit is located in the second frequency band, and the equivalent electrical length of a part, except the first resonant circuit, in the first reflector is smaller than one half of the wavelength of the second frequency band.

2. The directional antenna of claim 1, wherein a minimum frequency of the second frequency band is greater than a maximum frequency of the first frequency band.

3. The directional antenna of claim 1 or 2, characterized in that the active elements further comprise a third element, the operating frequency band of the third element is a third frequency band, and the first reflector further comprises a second resonant circuit connected in series with the first resonant circuit;

4. The directional antenna of claim 1 or 2, characterized in that the first reflector further comprises a conductive member connected in series with the first resonant circuit, the equivalent electrical length of the first reflector minus the equivalent electrical length of the conductive member being less than one half of the wavelength of the first frequency band.

5. The directional antenna of claim 3, wherein the first reflector further comprises a conductive member connected in series with the first resonant circuit, and wherein the equivalent electrical length of the first reflector minus the equivalent electrical length of the conductive member is less than one-half of a wavelength of the first frequency band.

6. A directional antenna according to any one of claims 1, 2 and 5, characterized in that the antenna further comprises a second reflector having an equivalent electrical length equal to or slightly greater than one-half of the wavelength of the second frequency band.

7. A directional antenna according to claim 3, characterised in that the antenna further comprises a second reflector having an equivalent electrical length equal to or slightly greater than one half of the wavelength of the second frequency band.

8. The directional antenna of claim 4, further comprising a second reflector having an equivalent electrical length equal to or slightly greater than one-half of a wavelength of the second frequency band.

9. The directional antenna according to any one of claims 1, 2, 5, 7 and 8, wherein the antenna further comprises a mounting plate, the mounting plate comprises a first mounting surface, a first functional layer is arranged on the first mounting surface, the first functional layer is made of a conductor, and the active element is located in the first functional layer.

10. The directional antenna of claim 3, further comprising a mounting plate, wherein the mounting plate comprises a first mounting surface, a first functional layer is disposed on the first mounting surface, the first functional layer is made of a conductor, and the active element is located in the first functional layer.

11. The directional antenna of claim 4, further comprising a mounting plate, wherein the mounting plate comprises a first mounting surface, a first functional layer is disposed on the first mounting surface, the first functional layer is made of a conductor, and the active element is located in the first functional layer.

12. The directional antenna of claim 6, further comprising a mounting plate, wherein the mounting plate comprises a first mounting surface, a first functional layer is disposed on the first mounting surface, the first functional layer is made of a conductor, and the active element is located in the first functional layer.

13. The directional antenna of claim 9, wherein the first capacitive element and the first inductive element are both located within the first functional layer.

14. The directional antenna of any of claims 10-12, wherein the first capacitive element and the first inductive element are both located within the first functional layer.

15. The directional antenna according to claim 9, wherein the mounting board further comprises a second mounting surface disposed opposite to the first mounting surface, a second functional layer is disposed on the second mounting surface, the second functional layer is made of a conductor, and the first capacitive element and the first inductive element are both disposed in the second functional layer, or the first capacitive element and the first inductive element are disposed in the first functional layer and the second functional layer, respectively, and the first capacitive element and the first inductive element are disposed opposite to each other.

16. The directional antenna according to any one of claims 10 to 12, wherein the mounting board further comprises a second mounting surface disposed opposite to the first mounting surface, a second functional layer is disposed on the second mounting surface, the material of the second functional layer is a conductor, and the first capacitive element and the first inductive element are both disposed in the second functional layer, or the first capacitive element and the first inductive element are disposed in the first functional layer and the second functional layer, respectively, and the first capacitive element and the first inductive element are disposed opposite to each other.

17. The directional antenna according to claim 9, further comprising a floor, wherein the floor includes a bearing surface, the bearing surface bears the mounting plate, an included angle between the bearing surface and the first mounting surface is less than or equal to 90 degrees, a conductive layer is disposed on the bearing surface, and the conductive layer is electrically connected to the active element and the first reflector.

18. The directional antenna according to any one of claims 10, 11, 12, 13, and 15, further comprising a floor, wherein the floor includes a bearing surface, the bearing surface bears the mounting board, an included angle between the bearing surface and the first mounting surface is less than or equal to 90 degrees, a conductive layer is disposed on the bearing surface, and the conductive layer is electrically connected to the active element and the first reflector.

19. The directional antenna of claim 14, further comprising a floor, wherein the floor comprises a bearing surface, the bearing surface bears the mounting plate, an included angle between the bearing surface and the first mounting surface is less than or equal to 90 degrees, a conductive layer is disposed on the bearing surface, and the conductive layer is electrically connected to the active element and the first reflector.

20. The directional antenna of claim 16, further comprising a floor, wherein the floor comprises a bearing surface, the bearing surface bears the mounting plate, an included angle between the bearing surface and the first mounting surface is less than or equal to 90 degrees, a conductive layer is disposed on the bearing surface, and the conductive layer is electrically connected to the active element and the first reflector.

21. A directional antenna according to any one of claims 17, 19 and 20, wherein said first reflector further comprises a control switch electrically connected between said first resonant circuit and said conductive layer;

22. The directional antenna of claim 18, wherein the first reflector further comprises a control switch electrically connected between the first resonant circuit and the conductive layer;

23. A communication device comprising a radio frequency module and a directional antenna according to any of claims 1-22, the radio frequency module being electrically connected to an active element of the directional antenna.